Why Leibniz Still Matters

Why study Leibniz today? There are many familiar answers to this question, and most of them are good ones. Leibniz is functionally relevant because many of his ideas are still alive in philosophical debate: possible worlds, the principle of sufficient reason, the identity of indiscernibles, the mill argument, and much else besides. He is historically relevant because his work is indispensable for understanding later developments, especially in German idealism. He is critically relevant because his philosophy challenges assumptions that remain powerful today: materialism, mechanistic causation, and the idea that reality must be understood primarily in terms of interaction between extended things. He may even be existentially relevant, since he thought his philosophy could console us by showing that the world is ordered by divine wisdom.

All of this matters, but Leibniz’s relevance does not lie only in the content of his doctrines, or in the later influence of his ideas, or in the ways he anticipated future developments, because in Leibniz’s case, we have something rarer: not just a philosophy, but a record of philosophy being done. Let’s explore this idea.

There is a familiar way of encountering the great philosophers. We meet Plato through the Republic, Descartes through the Meditations, Spinoza through the Ethics. These works present themselves as complete, self-contained, and systematically ordered. They do not merely contain arguments; they stand before us as monuments, giving us philosophy as a finished product. Leibniz does not quite fit this model. Although he is routinely placed alongside Descartes and Spinoza as one of the great rationalists, his legacy looks very different. There is no single work of Leibniz’s that occupies the same place as the Meditations or the Ethics. Instead, what we have is a vast and unruly archive: thousands of pages of notes, drafts, letters, fragments, sketches, abandoned beginnings, unfinished arguments, and writings never intended for publication. Most are undated; many seem provisional and exploratory; some even break off mid-thought.

This is often treated as a deficiency. Leibniz, on this view, is the philosopher who never quite finished the job: a brilliant but distracted polymath, forever sketching systems he did not consolidate. But this apparent failure may be one of his greatest gifts to us, because to read Leibniz’s drafts is to encounter philosophy in motion. The distinction between the messy process by which ideas are formed and the clean arguments by which they are later presented begins to collapse. In his papers, the process is not hidden behind the product; rather, the process is part of the product. We see Leibniz trying out formulations, abandoning them, returning to them, revising his terminology, multiplying distinctions, and pursuing several lines of thought at once. We see hesitation, experiment, contradiction, and repair. The result is less like a finished building than a workshop in which the tools are still on the bench.

That workshop quality is not merely of biographical interest: it has philosophical significance. The dominant image of philosophy, especially in canonical texts, is one of order: definitions laid down, arguments constructed step by step, conclusions drawn with necessity, or at least with an air of inevitability. Leibniz’s papers suggest another image, namely philosophy as an activity that is exploratory, recursive, and often inconclusive. Ideas do not emerge fully formed, but are worked and reworked, often in response to problems that themselves shift under pressure.

What is remarkable is not simply that Leibniz gets things wrong or changes his mind, as every serious thinker does that, but that the instability has been preserved. In a finished treatise, false starts are usually erased, earlier formulations disappear, and hesitations are smoothed away. The reader sees the conclusion, not the struggle that made it possible. In Leibniz’s Nachlass, by contrast, the struggle remains visible. The drafts, fragments, crossings-out, and unfinished notes allow us to follow thought as it develops.

This shifts our attention from philosophical results to philosophical practice. What does it actually look like to think philosophically? Not always like the orderly progression from premises to conclusion that one finds in textbooks. More often it looks like what we find in Leibniz’s papers: attempts made and withdrawn, distinctions introduced and refined, analogies explored and discarded, problems reopened, formulations tested, and old questions approached from new angles. In short, philosophical thinking is messy.

That messiness is not an embarrassment to be cleaned up but is part of the activity itself. Philosophy may aim at clarity, but it often reaches clarity through confusion. It may seek necessity, but it often proceeds through contingency, following lines of inquiry whose significance is not yet known and may at any point be abandoned. Leibniz’s drafts make this visible in a way that polished works do not and cannot. They show not only what philosophy achieves, but what it is like to practise it seriously.

This has a liberating effect. Academic philosophy can sometimes give the impression that one should speak only after achieving clarity, that the real task is to present one’s ideas in their final, defensible form. Leibniz’s example suggests otherwise. He shows that philosophy also happens before that point: in the provisional, the tentative, the half-formed, the unresolved. This is not to deny the value of finished works. We return to the Meditations and the Ethics precisely because they offer a level of articulation and coherence that drafts typically lack. But there is also a risk that the very qualities that make these works exemplary—clarity, completeness, systematicity—can obscure the process by which they were achieved. They can make philosophy seem smoother, cleaner, and more inevitable than it really is. Leibniz corrects that impression. He shows us a mind at work rather than a system at rest.

It reminds us that philosophical ideas are not simply discovered or deduced, but made: shaped through a process that is often circuitous and incomplete. And it suggests that there is philosophical value in attending to this process, not merely as a prelude to the “real” work but as part of the work itself.

In this sense, Leibniz’s drafts serve as a model of what it is to do philosophy. They show the uncertainty, the changes of direction, the unfinished thoughts, the testing of ideas, the dead ends, the experiments with terminology. In short, they show the work that goes on when one does philosophy. Doing philosophy is hard work, so hard that even one of the greatest thinkers who ever lived struggled with it like the rest of us.

And being able to see this has enormous value. It shows students and researchers what doing philosophy really involves. It gives access to the process, not just the final product. For that reason, we might call this kind of relevance “processual relevance”. A thinker has processual relevance when their writings reveal the process of philosophical inquiry itself: the real dynamics of thinking, not merely the treatise that may eventually emerge from it. Leibniz is unusually powerful in this respect because the survival of his papers allows us to see the labour of philosophy with exceptional vividness.

Leibniz himself might have been bemused by this claim. No doubt he would have wanted to be relevant because later thinkers found his doctrines true, useful, or illuminating. He may not have welcomed the suggestion that his unfinishedness is part of his value. Yet the historical accident that preserved so much of his intellectual workshop has given him a kind of relevance he could not have intended.

To study Leibniz today, then, is not only to engage with doctrines about substance, causation, possibility, God, and the order of nature, but also to witness philosophical thinking in its most exposed form. In an intellectual culture that often prizes the finished product over the process, this is no small gift. Leibniz’s drafts remind us of what it means to do philosophy at all, and to recognize that its vitality lies precisely in the fact that it is process as much as it is destination.

— Lloyd Strickland, 12.v.2026

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